.\" -*- nroff -*-
.\" Copyright 2013 Los Alamos National Security, LLC. All rights reserved.
.\" Copyright 2010 Cisco Systems, Inc.  All rights reserved.
.\" Copyright 2006-2008 Sun Microsystems, Inc.
.\" Copyright (c) 1996 Thinking Machines Corporation
.\" Copyright (c) 2020      Google, LLC. All rights reserved.
.\" $COPYRIGHT$
.TH MPI_Group_incl 3 "#OMPI_DATE#" "#PACKAGE_VERSION#" "#PACKAGE_NAME#"
.SH NAME
\fBMPI_Group_incl \fP \- Produces a group by reordering an existing group and taking only listed members.

.SH SYNTAX
.ft R
.SH C Syntax
.nf
#include <mpi.h>
int MPI_Group_incl(MPI_Group \fIgroup\fP, int\fI n\fP, const int\fI ranks\fP[],
	MPI_Group\fI *newgroup\fP)

.fi
.SH Fortran Syntax
.nf
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_GROUP_INCL(\fIGROUP, N, RANKS, NEWGROUP, IERROR\fP)
	INTEGER	\fIGROUP, N, RANKS(*), NEWGROUP, IERROR\fP

.fi
.SH Fortran 2008 Syntax
.nf
USE mpi_f08
MPI_Group_incl(\fIgroup\fP, \fIn\fP, \fIranks\fP, \fInewgroup\fP, \fIierror\fP)
	TYPE(MPI_Group), INTENT(IN) :: \fIgroup\fP
	INTEGER, INTENT(IN) :: \fIn\fP, \fIranks(n)\fP
	TYPE(MPI_Group), INTENT(OUT) :: \fInewgroup\fP
	INTEGER, OPTIONAL, INTENT(OUT) :: \fIierror\fP

.fi
.SH INPUT PARAMETERS
.ft R
.TP 1i
group
Group (handle).
.TP 1i
n
Number of elements in array ranks (and size of \fInewgroup\fP)(integer).
.TP 1i
ranks
Ranks of processes in group to appear in newgroup (array of integers).

.SH OUTPUT PARAMETERS
.ft R
.TP 1i
newgroup
New group derived from above, in the order defined by ranks (handle).
.ft R
.TP 1i
IERROR
Fortran only: Error status (integer).

.SH DESCRIPTION
.ft R
The function MPI_Group_incl creates a group group_out that consists of the n processes in group with ranks rank[0], \&..., rank[n-1]; the process with rank i in group_out is the process with rank ranks[i] in group. Each of the n elements of ranks must be a valid rank in group and all elements must be distinct, or else the program is erroneous. If n = 0, then group_out is MPI_GROUP_EMPTY. This function can, for instance, be used to reorder the elements of a group.

.SH NOTE
.ft R
This implementation does not currently check to ensure that there are no
duplicates in the list of ranks.

.SH ERRORS
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument.
.sp
Before the error value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

.SH SEE ALSO
.ft R
.sp
MPI_Group_compare
.br
MPI_Group_range_incl
.br
MPI_Group_free

